Add scroll_container[] (minor compatibility break)

README.md

@@ -24,7 +24,8 @@ A Minetest mod library to make modifying formspecs easier.
  - `formspec_ast.apply_offset(tree, x, y)`: Shifts all elements in `tree`.
     Similar to `container`.
  - `formspec_ast.flatten(tree)`: Removes all containers and offsets elements
-    that were in containers accordingly.
+    that were in containers accordingly. **The use of this function is
+    discouraged as `scroll_container[]` elements are not flattened.**
  - `formspec_ast.show_formspec(player_or_name, formname, formspec)`: Similar
     to `minetest.show_formspec`, however also accepts player objects and will
     pass `formspec` through `formspec_ast.interpret` first.
@@ -41,6 +42,12 @@ all attributes are lowercase.
 
 [the formspec element list]: https://github.com/minetest/minetest/blob/dee2210/doc/lua_api.txt#L1959
 
+### Recent backwards incompatibilities
+
+ - The `style[]` element has a `selectors` field instead of `name`. Using
+    `name` when unparsing formspecs still works, however parsed formspecs
+    always use `selectors`.
+
 ### Special cases
 
  - `formspec_version` (provided it is the first element) is moved to
@@ -73,7 +80,7 @@ readability.*
     },
     {
         type = "style",
-        name = "name",
+        selectors = {"name"},
         props = {
             bgcolor = "blue",
             textcolor = "yellow",
@@ -135,7 +142,7 @@ readability.*
     },
     {
         type = "style",
-        name = "name",
+        selectors = {"name"},
         props = {
             bgcolor = "blue",
             textcolor = "yellow",

core.lua

@@ -156,7 +156,7 @@ end
 local function parse_value(elems, template)
     local elems_l, template_l = #elems, #template
     if elems_l < template_l or (elems_l > template_l and
-            template[template_l][2] ~= '...') then
+            template_l > 0 and template[template_l][2] ~= '...') then
         while #elems > #template and elems[#elems]:trim() == '' do
             elems[#elems] = nil
         end
@@ -320,10 +320,12 @@ function formspec_ast.parse(spec, custom_handlers)
             return nil, err
         end
         table.insert(container, ast_elem)
-        if ast_elem.type == 'container' then
+        if ast_elem.type == 'container' or
+                ast_elem.type == 'scroll_container' then
             table.insert(containers, container)
             container = ast_elem
-        elseif ast_elem.type == 'container_end' then
+        elseif ast_elem.type == 'end' or ast_elem.type == 'container_end' or
+                ast_elem.type == 'scroll_container_end' then
             container[#container] = nil
             container = table.remove(containers)
             if not container then
@@ -348,6 +350,7 @@ local function unparse_ellipsis(elem, obj1, res, inner)
         end
     elseif type(obj1[2]) == 'string' then
         local value = elem[obj1[1]]
+        if value == nil then return end
         for k, v in ipairs(value) do
             table.insert(res, tostring(v))
         end
@@ -413,14 +416,15 @@ do
 end
 
 local function unparse_elem(elem, res, force)
-    if elem.type == 'container' and not force then
+    if (elem.type == 'container' or
+            elem.type == 'scroll_container') and not force then
         local err = unparse_elem(elem, res, true)
         if err then return err end
         for _, e in ipairs(elem) do
             local err = unparse_elem(e, res)
             if err then return err end
         end
-        return unparse_elem({type='container_end'}, res, true)
+        return unparse_elem({type=elem.type .. '_end'}, res, true)
     end
 
     local data = elements[elem.type]

helpers.lua

@@ -59,7 +59,7 @@ function formspec_ast.walk(tree)
         end
         i = i + 1
 
-        if res.type == 'container' then
+        if res.type == 'container' or res.type == 'scroll_container' then
             table.insert(parents, {tree, i})
             tree = res
             i = 1

init.lua

@@ -54,6 +54,7 @@ else
         end
         return text
     end
+    minetest.log = print
     function string.trim(str)
         return str:gsub("^%s*(.-)%s*$", "%1")
     end

make_elements.py

@@ -14,9 +14,9 @@ def _make_known(**kwargs):
 
 _known = _make_known(
     number=('x', 'y', 'w', 'h', 'selected_idx', 'version',
-            'starting_item_index'),
+            'starting_item_index', 'scroll_factor'),
     boolean=('auto_clip', 'fixed_size', 'transparent', 'draw_border', 'bool',
-             'fullscreen', 'noclip', 'drawborder', 'selected'),
+             'fullscreen', 'noclip', 'drawborder', 'selected', 'force'),
     table=('param', 'opt', 'prop'),
     null=('',),
 )
@@ -99,6 +99,24 @@ def _size_hook(params):
     yield params
     yield [[('w', 'number'), ('h', 'number')]]
 
+# Fix style and style_type
+@hook('style')
+@hook('style_type')
+def _style_hook(params):
+    # This is not used when parsing but keeps backwards compatibility when
+    # unparsing.
+    params[0] = [('name', 'string')]
+    yield params
+
+    params[0] = [(('selectors', 'string'), '...')]
+    yield params
+
+# Fix scroll_container
+@hook('scroll_container')
+def _scroll_container_hook(params):
+    yield params
+    yield params[:4]
+
 def _raw_parse(data):
     data = data.split('\nElements\n--------\n', 1)[-1].split('\n----', 1)[0]
     for line in data.split('\n'):

tests.lua

@@ -0,0 +1,181 @@
+-- dofile('init.lua')
+dofile('test.lua')
+
+local function equal(t1, t2)
+    if type(t1) ~= 'table' or type(t2) ~= 'table' then
+        return t1 == t2
+    end
+    for k, v in pairs(t1) do
+        if not equal(v, t2[k]) then
+            print(k, v, dump(t1), dump(t2))
+            return false
+        end
+    end
+    for k, v in pairs(t2) do
+        if t1[k] == nil then
+            return false
+        end
+    end
+    return true
+end
+
+local function assert_equal(obj1, ...)
+    for i = 1, select('#', ...) do
+        objn = select(i, ...)
+        if not equal(obj1, objn) then
+            error(('%s ~= %s'):format(obj1, objn))
+        end
+    end
+end
+
+local function test_parse(fs, expected_tree)
+    -- Make single elements lists and add formspec_version
+    if expected_tree.type then
+        expected_tree = {expected_tree}
+    end
+    if not expected_tree.formspec_version then
+        expected_tree.formspec_version = 1
+    end
+
+    local tree = assert(formspec_ast.parse(fs))
+    assert_equal(tree, expected_tree)
+end
+
+local function test_parse_unparse(fs, expected_tree)
+    test_parse(fs, expected_tree)
+    local unparsed_fs = assert(formspec_ast.unparse(expected_tree))
+    assert_equal(fs, unparsed_fs)
+end
+
+local fs = [[
+    formspec_version[2]
+    size[5,2]
+    container[1,1]
+        label[0,0;Containers are fun]
+        container[-1,-1]
+            button[0.5,0;4,1;name;Label]
+        container_end[]
+        label[0,1;Nested containers work too.]
+        scroll_container[0,2;1,1;scrollbar;vertical]
+            button[0.5,0;4,1;name;Label]
+        scroll_container_end[]
+    container_end[]
+    image[0,1;1,1;air.png]
+    set_focus[name;true]
+]]
+fs = ('\n' .. fs):gsub('\n[ \n]*', '')
+
+test_parse_unparse(fs, {
+    formspec_version = 2,
+    {
+        type = "size",
+        w = 5,
+        h = 2,
+    },
+    {
+        type = "container",
+        x = 1,
+        y = 1,
+        {
+            type = "label",
+            x = 0,
+            y = 0,
+            label = "Containers are fun",
+        },
+        {
+            type = "container",
+            x = -1,
+            y = -1,
+            {
+                type = "button",
+                x = 0.5,
+                y = 0,
+                w = 4,
+                h = 1,
+                name = "name",
+                label = "Label",
+            },
+        },
+        {
+            type = "label",
+            x = 0,
+            y = 1,
+            label = "Nested containers work too.",
+        },
+        {
+            type = "scroll_container",
+            x = 0,
+            y = 2,
+            w = 1,
+            h = 1,
+            scrollbar_name = "scrollbar",
+            orientation = "vertical",
+            -- scroll_factor = nil,
+            {
+                h = 1,
+                y = 0,
+                label = "Label",
+                w = 4,
+                name = "name",
+                x = 0.5,
+                type = "button"
+            },
+        },
+    },
+    {
+        type = "image",
+        x = 0,
+        y = 1,
+        w = 1,
+        h = 1,
+        texture_name = "air.png",
+    },
+    {
+        type = "set_focus",
+        name = "name",
+        force = true,
+    }
+})
+
+
+-- Make sure style[] (un)parses correctly
+local s = 'style[test1,test2;def=ghi]style_type[test;abc=def]'
+assert_equal(s, assert(formspec_ast.interpret(s)))
+test_parse('style[name,name2;bgcolor=blue;textcolor=yellow]', {
+    type = "style",
+    selectors = {
+        "name",
+        "name2",
+    },
+    props = {
+        bgcolor = "blue",
+        textcolor = "yellow",
+    },
+})
+
+-- Ensure the style[] unparse compatibility works correctly
+assert_equal(
+    'style_type[test;abc=def]',
+    assert(formspec_ast.unparse({
+        {
+            type = 'style_type',
+            name = 'test',
+            props = {
+                abc = 'def',
+            },
+        }
+    })),
+    assert(formspec_ast.unparse({
+        {
+            type = 'style_type',
+            selectors = {
+                'test',
+            },
+            props = {
+                abc = 'def',
+            },
+        }
+    }))
+)
+
+print('Tests pass')